Wednesday, March 26, 2014

Generators are the bane of my existence

Don’t get alarmed – our jurassic model Onan is purring away contentedly underneath me even as I type.  But that doesn’t happen by chance.  Its a never ending struggle to keep it keeping on.

Three days ago when we arrived in Vancouver the generator was hard to start.  That’s not completely unusual for it – I’ve come to know that these Onans are a cold blooded beast – they take a lot of preheat to light up when they’re cold.  On Sunday though it was simple lack of fuel.  Lack of preheat isn’t hard to recognize – it will burp and fart and generally complain but eventually it starts.  Lack of fuel, as I have preached numerous times before, is one of only two things that will stop these dead simple machines known as mechanical diesels.  Let me repeat it in case you missed it the first 30 times: if it turns over and it has fuel then it WILL run.  By extension, if it turns over and DOESN’T run, then it doesn’t have fuel.  With a mechanical diesel it really is that simple.

After I bled the pump I deduced that what had happened was that the big engines running on the trip over had sucked enough fuel out of the generator to airlock it and thus prevent it from getting fuel and thereby prevent it from starting.  But why had this happened all of a sudden you ask?  Well, somewhere there had to be an air leak in the fuel line to the generator which was allowing the engine fuel pumps to pull fuel from the generator rather than the fuel tanks.  As luck would have it, I found the leak relatively quickly.  There’s a little 1/8 street elbow that threads into the sediment bowl on the generator and it was very slightly loose. 

As anyone who has ever dealt with small diameter street elbows will know, this wasn’t a trivial problem to solve.  The problem with a small street elbow threaded into a housing is that it is usually done because there’s no damn room to work unless you use a rinky dink tiny fitting to connect to the housing.  When you thread in such a small fitting it usually only has a 20 or 30 degree range of motion where its usable and inevitably what happens is that you get to where its almost tight but its already in the right location.  Then you know that if you try to go another 360 degrees (to fully tighten it) then it will strip the threads in the POS housing you are threading it into and if you leave it where it is it will leak.  So I pulled it out and taped the hell out of the threads with teflon tape – that’s the only good use I know of for teflon tape – I use it so rarely that I had to go buy some. 

In addition to fixing the air leak I decided to put a check valve in the line to the generator where it branches off from the fuel manifold.  That should completely protect the generator from any future fuel starvation issues.  The problem with that plan was first finding a check valve and then finding the right assortment of fittings to plumb it into the system.  When George re-plumbed the fuel system he used SAE 45 degree flare fittings on the hoses with pipe threads in the manifold and shut-off valves.  45 degree flare fittings were probably the best choice but that didn’t make it any easier to find them here in Vancouver.

I used to think that the reason I had trouble specifying fittings to counter sales droids was because I was fundamentally stupid about fittings.  There is, after all a bewildering array of standards and styles of threaded fittings – pipe, ORB, SAE 45 flare, SAE 37 flare, inverted flare – I could go on.  I have lately come to the conclusion that the problem is not me but rather the parts droids themselves.  This morning I phoned a local plumbing shop and asked a very simple question: “Do you stock SAE 45 flare fittings?” “Yep, what do you need?” “Well I need two #5 male flare by 1/4” NPT male fittings”.  You can’t specify it any more clearly than that, I thought.  Boy was I wrong.  I should have hung up when he started telling me that #5 didn’t mean anything to him.  For those who don’t already know, SAE flare fittings are sized by number with the number representing the nominal pipe size in 16ths of an inch.  So a #5 fitting is nominal 5/16 pipe.  Eventually I did tell him that he didn’t know what he was talking about and hung up on him but those 5 minutes of my life are gone forever with nothing to show for them other than the memory of the frustration.

I ended up at a nearby Acklands counter for the flare fittings and the local Ukrainian Tire for the brass pipe fittings.  Everything is tightened back up now and the generator still runs.  We won’t know for sure whether I have fixed this problem until we’ve got a few days run time behind us.  And no doubt there’s many more generator related problems waiting in the wings.  One really great thing about life on a boat is that you are never short of something to do.

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